Motor vehicle suspension



y 1939- v. VALLETTA MOTOR VEHICLE SUSPENSION 2 Shets-Sheet 1 Filed Nov.18, 1957 Fig l ffl'o/ la lalem Patented July 4, 1939 UNITED STATESPATENT OFFICE MOTOR vamcm sosrsssron Application November 18, 1937,Serial No. 175,221

' In Italy January 30, 1937 1 Claims. (Cl. 207-19) This inventionrelates to motor vehicle wheel suspensions.

Independent wheel suspensions lack the transverse stifl'ening affordedin ordinary suspensions 5 by the rigid axles and the vehicle carriedthereby are subject to roll, 1. e. to incline excessively on one side indriving round a curve if a millcient flexibility be maintained duringconcordant raising and'lowering of both wheels with respect tothevehicle frame.

An attempt to obviate this drawback is the provision, in additionto thespring means for the independent suspension of the wheels, of atransverse torsion or anti-roll stabilizing bar; 16 but this is notwholly satisfactory, the said spring means remaining unmodified, andsimply resulting in increasing the number of resilient means for eachwheel pair from two to three, viz., the two original springs and thetransverse g torsion bar. Moreover, anti-roll stabilizing of the vehicleis due both to flexibility of the bar and of the ordinary suspensionsprings, which is paritcularly objectionable when adjustment isrequired, since pitching or flexibility of both wheels movingconcordantly, and rolling have opposite adjusting requirements,improvement of one being detrimental to the other.

It is an object of this invention to eliminate the above mentioneddrawbacks. A suspension according to the invention comprises a resilient.means arranged to alone counteract concordant vertical displacement ofthe two wheels with respect to thevehicle frame but not rolling, andanother resilient means interposed between the two wheels so as to alonecounteract rolling of the vehicle but not concordant verticaldisplacement of the wheelswith respect tov the frame.

The second mentioned resilient means may 40 consist of a transversetorsion bar mounted so as to be free to rotate about its own axis andconnected at its ends, in a manner known per se;

to the two wheels by'means of levers or the like.

With a suspension according to the invention,

45. when both wheels are raised with respect to the frame, theirflexibility in millimeters of displace ment per kg. of load variation,which may be represented by F1, is dependent only on the firstresilientmeans; when one wheel is-raised and the other is proportionately loweredwith respect to the frame rolling, the flexibility of the two wheels,which may be represented by Fn, depends upon the second resilient meansonly.

' I When one wheel only is lifted, its flexibility 56 is dependent uponboth resilient means; more by, means of pivots la in supports 8 arrangedat an effective stabilization. When-both wheels l0 particularly it willbe subjected to a resistance equal to the sum of the resistance thatwould be aiforded if both resilient means were to act simultaneously onthe wheel, this, however, with a useful length and, consequently, aflexibility 5 twice that occurring on each wheel in the first two cases.If Fm represents the third flexibility, it can be equated thus:

tfii from whichit will be seen how it is also possible to increase Fmwithout increasing Fu (1. e. rolling) but only F: (i. e. the flexibilityfor concordant movement of both. wheels).

The accompanying drawings show, by way of example, twd constructionsaccording to the invention. 1

Fig, 1 is a plan, partly in section, of the flrst 20 construction.

Fig. 2 is an elevation, partly in section, of the flrst construction.

Fig. 3 is a plan of the second construction.

H8. 4 is an elevation of the second construc- 25 tion, partlyin sectionon the line IV-IV of Fig. 3.

Referring to Figs. 1 and 2, a support 2 is attached to the lower portionof the vehicle frame I and has articulated thereto, by means of a pivotpin 3, the stirrup 4 of a cross leaf spring 6. The ends of the leafspring are suspended by means of members 6 from levers .i which extendapproximately in the longitudinal direction of the vehicle and which arejournalled the ends of a tubular member 9 secured to the frame I. Thewheels iii are mounted at the opposite ends of the levers l. The twopivots la about which the levers l oscillate are connected to each otherby means of a transverse torsion bar II which is free to turn in bothsupports 8. I when, for instance, the right wheel i0 is lifted and theleft one is proportionately lowered with respect to the frame i(rolling), as occurs on taking a left-handed curve, the leaf spring 5 isnot deformed but undergoes only an angular displacement about the pivot3; the bar ii then comes into action and undergoes torsion to give arelifted concordantly, the bar ll performs an angular displacement overits whole length with out being subjected to torsion, and in this casethe leaf spring 5 counteracts the movements of the two wheels.

Referring to Figs. 3 and 4, the two wheels ID are connected to the frameby means of transverse articulated parallelogram comprising top links l2and bottom links IS. The bottom links 13 are keyed to pivot pins (4arranged in a transverse housing l5 having mounted thereon horns orsupports l6 for the top links [2. Said housing l 5 contains a helicalspring I! having end collars engaged by the spherical ends of levers l8keyed one to each of the pivot pins ll.

Each bottom link I3 is provided with two bridge members 20 affording abearing for the spherical end of a link 2| whose other spherical end isjournalled in a spherical seating in an arm 22!: forming part of atransverse torsion bar 22 mounted so as to be free to rotate in supports23 fast to the housing i5.

It will be obvious that lowering of one wheel l0 accompanied by aproportionate lifting of the other wheel with respect to theframerolling, as occurs for instance on driving round curves, does notentail a deformation of the helical spring I! but only a displacementthereof towards the right or the left; in this case, however, thetorsion bar 22 comes into action as stabilizer. On the other hand,whenthe two wheels ID are raised concordantly the helical spring l! isdeformed while the torsion har does not undergo any deformation.

In both the constructions described, when only onewheel i8 is raised,this movement is absorbed by the led spring 5 (Figs. 2 and Z) or by thehelical spring ll (Figs. 6 and 4) together with the torsion bar H or 22.Nevertheless, the suspension is no stiffer than a comparable independentwheel suspenslon of known construction for both resilient means act overtheir whole length and thus afford a considerably increased flexibility.V

The invention is not to be taken as limited to the constructions hereindescribed and illustrated, which may be varied without departing fromits scope.

What I claim is:

1. A motor vehicle wheel suspension comprising two resilient means for apair of wheels, in which the first resilient means is arranged to alonecounteract concordant vertical displacement 0! both wheels with respectto the vehicle frame, and the other resilient means is interposedbetween the two wheels so as to alone counteract rolling of the vehicle.

2. A suspension according to claim 1, wherein the two resilient meansare arranged to operate over their whole length when only one of the twowheels is vertically displaced with respect to the vehicle frame.

3. A motor vehicle wheel suspension comprising a transverse torsion barmounted in the vehicle frame so as to be free to turn about its ownaxis, an arm for either wheel attached to the end of said torsion barand connected for oscillation with its respective wheel, a helicalspring, a lever for each wheel connected with them for oscillation, bothlevers being arranged to act on the ends of said helical spring inopposite directions.

VITI'OEIO VAILELIA.

